Catheter

ABSTRACT

A combination catheter and drainage system includes a flexible tubular member oligodynamically treated in part and having an aperture adjacent said one end to allow communication between a main lumen and the exterior of the tubular member, a balloon being provided adjacent the aperture and an auxiliary lumen being connected to the main lumen for inflating the balloon and a urine collecting bag connected to the tubular member via a connector means which is oligodynamically treated. The collecting bag is also provided at its discharge distal end with an oligodynamically active metal device thereby forming a system which is completely closed against entry of ambient microorganisms.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a divisional application of my copending applicationSer. No. 470,690, filed Feb. 28, 1983, now U.S. Pat. No. 4,483,688issued Nov. 20, 1984, which is a continuation-in-part of my applicationSer. No. 189,244 filed Sept. 22, 1980 now abandoned which is acontinuation-in-part of my application Ser. No. 923,440 filed July 10,1978, now abandoned, which is a continuation-in-part of my applicationSer. No. 740,285 filed Nov. 9, 1976, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a catheter and drainage system and moreparticularly to improvements therein whereby bacterial intrusion intothe system is effectively barred. 2. Prior Art

As is well known, the patients who have suffered from cerebrospinaldiseases such as cerebral hemorrhage, softening of brain or spinalinjuries, tend to be afflicted with dysuria of incontinence of urine. Itis therefore necessary in such instance that a urinary catheter beinserted into the urethra and retained in the appropriate position forurination for such patients as well as for those who have undergonevarious surgical operations. Such catheters are often called "indwellingcatheters," which must be sufficiently mechanically soft and resilientfor effective use.

While the indwelling catheter is retained in the urethra for arelatively long period of time, it would permit pathogenic bacteriaattached to the anus or genital vulva to enter through the urethra intothe bladder, thereby frequently causing cystitis, ureteritis, orpyelitis or the so-called "ascending infection." This is pronouncedparticalarly with female because her urethra is wider, shorter, and morelinear than that of male.

Various attempts have been made to prevent the bacterial infectionduring the use of such indwelling catheters. One such attempt has beento coat the catheter with an ointment containing an antibiotic orbactericide. Another attempt has been to irrigate the bladder throughthe catheter and wash the catheter at frequent intervals, and at thesame time to administer the patients with antibiotics for prophylacticpurposes. These proposals, however, are tedious and time-consuming, andare not completely free from renewed invasion by pathogenic bacteria.

Indwelling catheters are nowadays used in combination with urinedrainage devices of either an open-circuit or closed-circuit design. Theclosed drainage system has been preferred to delay infection in patientswith long-term urethral catheterization by virtue of its isolation fromthe ambient. Reportedly, however, more than 60 percent of the patientscatheterized in closed drainage systems are infected within about sevendays due to intrusion of bacteria from between an exposed portion of thecatheter and the mucous membrane of the urethra, between the catheterand the drainage tube, or from the junction between the urine collectingbag and the drainage tube.

SUMMARY OF THE INVENTION

The present invention seeks to provide an improved indwelling catheterwhich will prevent urinary tract infections or ascending infection dueto pathogenic bacteria while the catheter is being used.

According to an important aspect of the invention, there is provided acombination catheter and drainage system of a closed design forinfection-free long-term catheterization. The indwelling catheterprovided in accordance with the invention comprises a flexible tubularmember having a main lumen for urine discharge, one end of the mainlumen being closed by a tip, the tubular member having an apertureadjacent said one end to allow communication between the main lumen andthe exterior of the tubular member, and a balloon provided adjacent theaperture, an axillary lumen connected to the main lumen for inflatingthe balloon, an oligodynamically active metal deposited on the peripheryof the tubular member for producing metal ions upon contact with theurine.

The oligodynamic metal used in accordance with the invention istypically a heavy metal such as copper, silver, gold or their alloysincluding intermetallic compounds thereof. It has now been found thatthese metals exert in the form of metal ion concentrations only of theorder of about 1×10⁻⁶ M a profound bactericidal effect.

According to another important aspect of the invention, the indwellingcatheter is applied with an oligodynamically active coating only at itsoutside periphery, whereby the outside diameter of the catheter tube perse can be reduced to a minimum with the inside diameter maintained at amaximum to provide comfortable catheterization and smooth and effectivedrainage of urine.

Prior art counterparts are coated on both the outside and insidesurfaces of the catheter tube and hence have a drawback in that the tubeis necessarily smaller in inside diameter for a given outside diameterand susceptible to inner surface irregularities due to coating with theresult that not only the flow of urine is retarded or otherwise blockedbut also such coated interior can become a site for bacterial growth.

According to a preferred embodiment of the invention, the coatedcatheter is connected to a urine collecting bag having a drain pipe bymeans of a connector fitted between a flared outlet end of the catheterand a drainage tube leading to the bag, the connector and the drain pipebeing also plated or coated with an oligodynamic metal. This arrangementensures oligodynamic protection against urinary tract infections at allpoints of origin that may be disposed for contact with the ambientatmosphere.

The invention will now be described in greater detail, by way ofexample, with reference to the drawings, in which like referencecharacters refer to like and corresponding parts throughout the severalviews and in which:

BRIEF DISCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary plan view of a catheter equipped with ananchoring balloon;

FIG. 2 is an enlarged, partly cross-sectional view of the catheter shownin FIG. 1;

FIG. 3 is a cross-sectional view taken along the line III--III of FIG.2;

FIG. 4 is a plan view of a catheter according to another embodiment ofthe invention;

FIGS. 5 and 6 are schematic views illustrating the manner in which theballoon catheter is inserted in the male's and the female's urethra,respectively;

FIG. 7 is a plan view of the balloon catheter of FIG. 1 (or FIG. 4)shown as connected to a urine collecting bag;

FIG. 8 is a plan view of a connector adapted to connect the catheter toa drainage tube;

FIG. 9 is a schematic view utilized to explain the manner in which apatient lying on bed is being catheterized in accordance with theprinciples of the invention;

FIG. 10 is a schematic view utilized to explain the manner in which thesystem of the invention is applied to a pedestrian patient;

FIG. 11 is a graph illustrating the performance curve of the inventionas against that of the prior art counterpart; and

FIG. 12 is a schematic view of a prior art catheter and drainage system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference to FIGS. 1 to 3 inclusive shows a urethral catheter 10equipped with an anchoring balloon 11. The balloon catheter 10 comprisesa tube 12 made of rubber or plastics having a main lumen 13 and anauxiliary or inflation lumen 14 attached to the wall of the primarylumen 13. One end of the tube 12 is closed by a cap 15 made of copper orsilver and having a hole 16 through which urine is taken into the mainlumen 13. The cap 15 has on its bottom end a circular flange 17 fittedin the tube 12. Alternatively, the cap 15 may be integral with the tube12. A balloon-forming layer 18 is provided beneath the cap 15 and over arecess 19 in the exterior surface of the tube 12. An aperture 20 isformed in the tube wall to provide communication between the inflationlumen 14 and the exterior recess 19. The inflation lumen 14 extendsalong the tube 12 and is branched off to be connected to an inflationtube 21. A suitable inflation medium is injected from the inflation tube21 through the inflation lumen 14 and through the aperture 20 to expandthe layer 18 to a balloon-like configuration as shown in FIG. 2. Fordischarge of urine, the main lumen 13 is open at a flared end of thetube 12 opposite to the distal end where the cap 15 is located. Beneaththe balloon layer 18, an oligodynamically active metal coil 22 measuringabout 0.05 to 0.5 mm in diameter is wrapped around the tube 12. Similarcoils 22 are provided at spaced intervals along the length of the tube12. These coils must be embedded to keep their outer peripheral surfaceslying substantially flush with the exterior surface of the tube 12.

In use the balloon catheter 10 is inserted into the male's urethra 23 orfemale's urethra 24, and an inflation medium is pumped through theinflation lumen 14 to expand the anchoring balloon 11, as illustrated inFIGS. 5 and 6. This prevents accidental disengagement of the catheter 10from the patient and anchors the catheter 10 in the appropriate positionfor efficient use. With the catheter 10 thus anchored in the urethra,urine can be drained from the bladder 31 or 32 through the main lumen13. When the catheter is no longer needed, the balloon 11 is deflated byreleasing the inflation medium and the catheter 10 is removed from thepatient.

The embodiment shown in FIG. 4 is characterized by the application tothe exterior of the tube 12 of a silver or other oligodynamically activemetal in a powdery form ranging in particle size between 200 and 300mesh. The metal powder is dispersed in suitable binders and coated on aportion of the outer peripheral surface of the tube 12 at spacedintervals along the length thereof as at 25 corresponding in position tothe coils 22 of the catheter 10 shown in FIG. 1, the oligodynamicallytreated areas being determined by the length of the male or femaleurethra. The catehter 10 shown in FIG. 4 has a rounded tip 26 of rubberor plastic similar to the material of the tube 12 and is devoid of themetal cap 15.

The embodiment in which the oligodynamic coating 25 is applied in lieuof the coil 22 is preferred because the coating 25 being applied to aminimum thickness retains flexibility of the tube 12 to provide morecomfortable catheterization especially for long-term patients takinginto account the fact that the mucous membrane of the urethra isextremely sensitive to inflation, irritation or foreign matters. Forcomfortable usage, the catheter 10 should be as small in outsidediameter as possible. At the same time, its inside diameter should belarge enough to maintain smooth flow and drainage of urine. This dualfeature is achieved by the concept of applying the oligodynamic coatingonly to the outside surface of the tube 12 while the inside of the tube12 is left intact. The thickness to which the coating 25 is applied maybe of the order of 300-600 microns.

It is reported that a grown-up male in health urinates over twenty fourhours an average of 1,000-1,500 c.c. of water and 55-70 grams of solids,but patients' urine contains considerable waste materials that aresedimented or deposited, or crystallized medicaments. Hospitalizedpatents' smooth muscles do not function properly for urination andtherefore rely on the gravity of flow, for which purpose the innerperiphery of the tube 12 should be smooth and free of irregularitieswhich would otherwise result from coating or other treatment of theinterior of the tube 12.

In indwelling urethral catheterization, the catheter 10 is connected tourine collecting bag 27 via a drainage tube 28 to permit uninterrupteddrainage of urine from the patient as shown in FIG. 7. A connector 29 isadapted to join the flared outlet end of the tube 12 to one end of thedrainage tube 28, the other end of this tube being connected via aconnector 30 to the bag 27. The connector 29 may be of any known formand construction, an example being shown in FIG. 8. Importantly, theconnector 29 according to the invention is plated or coated with silveror other oligodynamically active metals to provide an effective barrieragainst intrusion of ambient infecting organisms from the junction intothe urinary tract and up towards the bladder. The junction 30 betweenthe drainage tube 28 and the bag 27 is provided with a pipe 31 made ofcopper which also has an oligodynamic activity for eliminating bacteriathat may ascend from the bag 27. The urine collecting or drainage bag 27is well known and shown as a closed drainage system which is preferredover an open system in recent years to delay infection in patients withlong-term urethral catheterization.

At the bottom of the bag 27 is provided a discharge outlet 32 which isattached with a clamp 34 and also connected to a copper pipe 33 capableof oligodynamically preventing entry of bacteria from the ambientatmosphere.

EXAMPLE

A balloon catheter 10 was coated with silver particles of about 300 meshover a length of 55 to 60 mm at a position about 5 mm below the lowerend of the balloon 11. These catheters each connected to a urinecollecting bag 27 were used in a total of 102 patients (40 males and 62females) hospitalized at St. Lukes' International Hospital in Tokyo forbladder catheterization after surgical operations or in those withurinary retention for periods ranging from 4 to 77 days. No antibiotictherapy was administered except for pneumonia for 2 cases over a shortperiod of time. All the cases ranging in age from 18 to 80 were free ofurinary bacteria prior to the use of the inventive system. For long-termcatheterization, the replacement of new system sets was made every 7days. Urine was sampled with a needle through sterilized spot of thecatheter in an open drainage system. Initially, urine samples werecultured daily but since the cultures done for a week were negative forbacteria in the first 5 cases they were done at intervals of 2 days to aweek in the remaining patients. Quantitative urine cultures were doneusing heart infusion agar plates that were incubated at 37° C. for 48 to72 hours. During the period of indwelling catheterization, noantibiotics, as a rule, were administered but no patient developed overbacteriuria (over 10⁵ bacteria per ml) or symptoms of urethritis.

In contrast, all of 20 patients in the control group who had indwellingcatheters of conventional type developed bacteriuria with 4 days ofcatheterization.

The data obtained and shown in Tables 1 and 2 indicate that effectiveprevention of urinary tract infection which is frequently associatedwith indwelling urethral catheterization can be achieved by the use ofthe catheter and drainage system provided in accordance with theinvention.

RESULTS

The ages of the 102 patients ranged from 18 to 80 years. Duringcatheterization none had bacteriuria (defined as containing a minimum of10⁵ bacteria per ml.) (Tables 1 and 2) or pyrexia more than 38.5° C. Ofthe patients 62 percent showed an increase in temperature to 38.0° C. 1or 2 days after catheterization, possibly owing to the influence of thepreceding operation. In no case were there symptoms or signs of acuteurethritis frequently associated with indwelling catheterization, thatis urethral discharge, a constant itching or burning sensation in theurethra, and reddening and edema of the external meatus. Followup 1 to 4months after removal of the catheter revealed no significant adversefindings in any of the 102 cases studied.

In contrast, all of the 20 control patients had bacteriuria within 4days (mean 48 hours) of indwelling catheterization. Pyrexia more than38.5° C. occurred in 5 cases (25 percent), urethral discharge in 15 (75per cent), itching or burning sensation in the urethra in 4 (20 percent)and reddening and edema of the external meatus in 2 (10 percent).

                                      TABLE 1                                     __________________________________________________________________________    Cases of Prolonged Catheterization                                                                      Duration of                                                                   catheterication                                                                       Fever          Symptoms of                  Case                                                                             Age                                                                              Clinical diagnosis                                                                        Operation                                                                             (days)  (38.5° C.)                                                                    Antibiotics                                                                           urethritis                                                                           Bacteriuria*          __________________________________________________________________________    1  79 (1)                                                                             Encephalomalacia  77      +      +       --     --                          (2)                                                                             Compression               (pneumonia)                                                                          (for pneumonia)                              fracture of Th.sub.12                                                         and L.sub.3                                                           2  43 (1)                                                                             Pelvic    Abdominal                                                                              9      --     --      --     --                            endometriosis                                                                           hysterectomy                                                      (2)                                                                             Teratoma of rt.                                                                         +                                                                   ovary     bilateral                                                                     adnexectomy                                                 3  32 Cervical incom-                                                                           Schirodkar's                                                                           8      --     --      --     --                          petency     operation                                                   4  65 Apoplexy            15      --     --      --     --                    5  52 Hemiplegia          25      --     --      --     --                    6  55 Adenocarcinoma of                                                                         Abdominal                                                                             10      --     --      --     --                          Lt. ovary   hysterectomy                                                                  +                                                                             bilateral                                                                     adnexectomy                                                 7  68 (1)                                                                             Prolapsus uteri                                                                         Abdominal                                                                             11      --     --      --     --                          (2)                                                                             Arthritis hysterectomy                                                        deformans                                                             __________________________________________________________________________     *over 10.sup.5 bacteria per ml.                                          

                  TABLE 2                                                         ______________________________________                                        Comparison of clinical effects of                                             catheterization with inventive type                                           and conventional catheter                                                                      Type of catheter                                                              Inventive                                                                             Conventional                                                          (102 cases)                                                                           (20 cases)                                           ______________________________________                                        Duration of catheterization                                                                      4-77      3-4                                              (days)                                                                        Bacteriuria        none      20                                               (over 10.sup.5 bacteria per ml)                                                                            (within 4 days,                                                               average 2 days)                                  Fever (38.5° C.↑)                                                                   none      5                                                Symptoms of                                                                            Urethral discharge                                                                          none      15                                           urethritis                                                                             Itching or burning                                                                          none      4                                                     sensation                                                                     Reddening or edema                                                                          none      2                                                     of external meatus                                                   ______________________________________                                    

The tablated results were obtained with use of the conventional opendrainage system typically shown in FIG. 12, in which reference numeral101 corresponds to part 11; reference numeral 102 to part 12; referencenumeral 103 to part 29; reference 104 to part 28; and reference numeral105 to part 27. The illustrated system is literally open for intrusionof bacterium from the exposed area, and the bacteria ascend after beingcultured in the bag or directly through the drainage tube. The interiorof the bag or the tube is moist and becomes a site for rapid bacterialgrowth which is known as "doubling" which takes place about every 20minutes.

Referring now to FIG. 11 which graphically illustrates the risks ofbacteriuria, the curve I represents the result of the open drainagesystem in which 100 percent of the patients showed the symptom ofurinary tract infection within 4 days. The curve II represents theresult of the conventional closed drainage system in which 30 percent ofthe patients were found infected within 4 days and 60 percent within 7days. In contrast to these conventional systems, the improved closedcatheter and drainage system according to the invention showed noappreciable signs of infection even after 10 days of catheterization asrepresented by the curve III.

In practice, the inventive system may be applied to a patient lying onbed 43 in a manner illustrated in FIG. 9, in which reference numeral 40corresponds to part 10; reference,numeral 41 to part 28; represencenumeral 42 to part 29; reference numeral 46 to part 27; referencenumeral 47 to part 31; reference numeral 48 to part 33; and referencenumeral 49 to part 34. The drainage system in FIG. 9 is shown secured tothe bed 43 with the drainage tube 41 pinned as at 44 and taped as at 45.

Alternatively, the system may be attached to the thigh of a pedestrianpatient in a manner shown in FIG. 10, in which reference numeral 51corresponds to part 27; reference numeral 52 to part 31; referencenumeral 53 to part 28; and reference numeral 54 to part 33. In thisembodiment, the bag 51 is attached to the thigh of the patient by meansof tapes or bands 50 to allow him to walk with the system on. Designatedat 55 is a socket threadedly engaged with the pipe 54.

In either of the embodiments shown in FIGS. 9 and 10, the importantconcept underlying the invention is embodied in which all possiblesources of entry of ambient bacteria as at 42, 47 (52), and 48 (54), arecovered by oligodynamically active means to protect the patient againsturinary tract infection.

Although various minor modifications may be suggested by those versed inthe art, it should be understood that I wish to embody within the scopeof the patent warranted hereon, all such embodiments as reasonably andproperly come within the scope of my contribution to the art.

What is claimed is:
 1. A catheter and drainage system adapted to becarried by a person and utilized to drain urine from a to-be-drainedbody cavity of said person to a drainage bag carried by said personcomprising, in combination, an indwelling catheter adapted to extendpartially into said body cavity, said catheter comprising a flexibletubular member having a main lumen for urine discharge, one end of saidmain lumen being closed, said tubular member having an aperture adjacentto said one end to allow communication between said main lumen and theexterior of said tubular member, a balloon provided adjacent saidaperture, an auxiliary lumen connected to said main lumen for inflatingsaid balloon, an oligodynamically active metal deposited on a portion ofonly the outside periphery of said tubular member for producing metalions upon contact with the urine, a urine collecting bag adapted to becarried by said person, said collecting bag having an inlet, and atubular sterilizing means having oligodynamic activity connecting saidcatheter tube to said inlet of said collecting bag.
 2. A draining systemadapted to be carried by a person and utilized to conduct body fluidsfrom an insertable device extending partially into a to-be-drained bodycavity of said person to a drainage bag carried by said person, thecombination corprising a catheter tube adapted to extend partially intosaid body cavity, said catheter tube being coated with anoligodynamically active metal only on the outside periphery forproducing metal ions upon contact with said body fluids, a drainage bagadapted to be carried by said person, and a connector means connectingsaid catheter tube to said drainage bag, said connector neans having anoligodynamically active metal to provide a barrier against intrusion ofambient infecting organisms into said catheter tube.
 3. A drainingsystem according to claim 2, wherein said connector means comprises atubular member having an oligodynamically active metal deposited on theoutside surface thereof to provide a barrier against intrusion ofambient infecting organisms into said catheter tube and up toward thebody cavity.
 4. A draining system according to claim 2, wherein saidconnector means comprises a pipe made of copper.
 5. A draining systemaccording to claim 2, wherein said oligodynamically active metal isselected from the group consisting of silver, gold, copper, theiralloys, and intermetallic compounds thereof.
 6. A draining systemadapted to be carried by a person and utilized to conduct body fluidsfrom an insertable device extending partially into a to-be-drained bodycavity of said person to a drainage bag carried by said person, thecombination comprising a catheter tube adapted to extend partially intosaid body cavity, said catheter tube being coated with aoligodynamically active metal only on the outside periphery forproducing metal ions upon contact with said body fluids, a drainage bagadapted to be carried by said person, said drainage bag having an inlet,and an oligodynamically active tubular member connecting said cathetertube to said inlet of said drainage bag, said oligodynamically activetubular member precluding bacteria from ascending from said drainagebag.
 7. A draining system adapted to be carried by a person and utilizedto conduct body fluids from an insertable device extending partiallyinto a to-be-drained body cavity of said person to a drainage bagcarried by said person, the combination comprising a catheter tubeadapted to extend partially into said body cavity, said catheter tubebeing coated with an oligodynamically active metal only on the outsideperiphery for producing metal ions upon contact with said body fluids, adrainage bag having an inlet and an outlet, a first oligodynamicallyactive tubular member connecting said catheter tube to said inlet ofsaid drainage bag, said first oligodynamically active tubular memberprecluding bacteria from ascending from said drainage bag, a secondoligodynamically active tubular member connected to said outlet of saiddrainage bag and oligodynamically preventing entry of bacteria from theambient atmosphere, and a removable closure member on said secondoligodynamically active tubular member.